Airtightness Testing

Airtightness Testing

Aldas are the most experienced Airtightness testers and consultants in the UK. We undertake bespoke and complex testing and leakage investigations, also thermographic inspections. For challenging and major projects requiring exceptional airtightness, Aldas will work with you to develop a solution.

About Us

Introduction to airtightness

Airtightness shows quality in a building. Airtightness makes ventilation/heating systems work properly whilst improving insulation’s effectiveness. This helps with reducing our fuel bills and increases health & comfort through the elimination of mould and condensation.

How do we measure airtightness?

We measure airtightness by temporarily mounting a calibrated fan in a window or door opening. We then take a series of readings of imposed pressure differential against the airflow generated by the fan – which is a function of (a) how big the building is and (b) how airtight (or otherwise) the building is.

What equipment is used in airtightness testing?

When carrying out airtightness testing, we use the following;
One or more calibrated fans, temporarily mounted in an open door or window.
Control equipment
Pressure gauges
Thermometers
Barometers
Tape measures

How do I oversee or witness an airtightness test?

For an airtightness test to be valid, several conditions must be met;
The test equipment must have a current calibration certificate
The test engineer must be competent to test the building using the applicable standard
The zero-flow pressure differentials are low enough
The building must be ready to test

How do I prepare for the test?

An Air Tightness Test (which is also known as air leakage test, air pressure test or air permeability test) is a government regulated test to ensure buildings do not leak or retain too much air.

Before an air test is carried out, we need to make sure the building is complete and is clear of all trades in order to achieve the best results possible.

The following criteria should be followed to provide you with the best chance of passing an air test:
1) All fixtures and fittings are installed including lights and sockets.

2) Every service penetration is sealed
All plumbing work is complete with water in the traps.

3) Seal skirting boards in every room
Gaps within walls and floors must be sealed.

4) Bathrooms and kitchens must be fully fitted and mastic sealed.

5) No work trades to be in the building where the test is carried out.

6) All external and internal windows and doors must be installed and closable.

7) The loft hatch is fitted and sealed.

8) 240V power being available in the plots being tested.

Risks in Airtightness

Key Risks associated with airtightness include:
Failing the airtightness test. The most common problem for a contractor or designer. Likely to mean extra sealing works for the contractor, possibly even design issues needing consideration (e.g. discovering that dot-and-dab plasterboard finishes cannot deliver the specified airtightness).
Poor airtightness. This usually means that the property under test is too leaky. But at the other end of the spectrum, ventilation can prove inadequate as the airtightness is improved. This can give rise to condensation and mould, with damaging health impacts.
For many years we have applied the slogan:
Build tight, ventilate right
These days, we try to avoid adding pollutants within a building, from paints, carpets and coverings, furniture. But the biggest issue is usually water. Water in the air leaking through the fabric of our buildings is likely to condense en-route, leading to damaging moisture in walls and roof spaces.

What standards are applied for airtightness?

Airtightness testing in the UK is governed by ATTMA, the Air Tightness Testing and Measurement Association. This is part of BCTA, the Building Compliance Testers Association.

Pre-Improvement

Preliminary Tests

Acceptance Tests

Thermographic
Surveys

Our Services

Domestic

Commercial

Design Guidance

Passivhaus

Retrofit

Aldas Coverage

Aldas have been involved in many interesting projects, both residential and commercial, big and small. We will always try to help where we can so please get in touch with us.

Our Testing Team

Aldas reliably delivers airtight buildings

Paul Jennings

Airtightness consultant. FOUNDER

Paul Jennings of Aldas is the most experienced airtightness tester and consultant in the UK, with over 30 years’ experience.

Paul is an experienced trainer and originated the “Airtightness Champion” concept, as well as delivering numerous on-site trainings and many CPD seminars to architects and builders. He developed the 12 Steps to Airtightness approach to enable UK contractors to reliably deliver airtightness in Passivhaus and other low-energy projects.

He has presented at many conferences and demonstrated test equipment at others. He has also given talks at Passivhaus conferences in Vancouver and Germany, as well as in the UK. Paul has been involved in most UK Passivhaus projects in one or more capacities. He is also a Director of the UK Cohousing Network.

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Mischa Hewitt

Airtightness consultant

As well as working with Aldas, Mischa is an energy consultant with Earthwise with a particular interest in affordable low energy buildings made from natural materials. He has been working on domestic and commercial environmental buildings since 2003 and holds an MSc in Sustainable Architecture with Distinction from the Centre of Alternative Technology.

Mischa is a Certified Passivhaus Designer and Air Pressure Tester. He is the co-author of the book Earthships in Europe and has written numerous articles on sustainable construction. Mischa is also a Trustee of the AECB – the Sustainable Building Association.